BC127 - Melody 6.1.5 firmware update

IoT Modules WiFi and Bluetooth Modules
1

Hi,

I am looking for the latest firmware update Melody 6.1.5 for BC127 on Blue Creation site or Sierra Wireless site. However, I can’t find it : bluecreation.com/firmwareupdates.php

The change log in bc127 documentation shows that Melody 6.1.5 exists and that new features are available :
bluecreation.com/MelodyAudi … e_log.html

I am interested in the auto_rate option of audio_digital parameter that is only available in Melody 6.1.5 firmware.

Can you tell me how to access this new firmware?

Thank you

2

Hi,

The release notes appear to be a few days ahead of the other parts of the site, it will either go onto the source or the BC website shortly.

Regards

Matt

3

Can you tell me when the firmware 6.1.5 is going to be available online?

Thank you

4

Hi,

There seems to be some discussion on this release with the team at the moment, the release notes might have been put on line a little prematurely. Hopefully have some more information on Friday.

Regards

Matt

5

6.1.5 is available now FYI

6

I just installed the Melody 6.1.5 firmware to experiment with the new auto_rate ON/OFF feature of AUDIO_DIGITAL.

Here is the experiment: (The BC127 is a I2S bus master, and a ARM based controller provides a tone-sweep signal)
RESTORE
UNPAIR
SET AUDIO=1 1
SET AUDIO_DIGITAL=0 44100 32 100A00 OFF
SET PROFILES=0 0 0 1 0 0 0 0 0 0 0 0
WRITE
RESET

1st experiment:
PAIR
OPEN A2DP
STATUS -> LINK 10 CONNECTED A2DP STREAMING SBC 44100

Observation => high quality audio, no clicks.

2nd experiment:
SET CODEC=6 OFF // Enable APTX_LL
WRITE
RESET
UNPAIR
PAIR
OPEN A2DP
STATUS -> LINK 10 CONNECTED A2DP STREAMING APTX_LL 44100

Observation => high quality audio but with a ‘click’ every second or so.

This result is still a big improvement over previous firmware releases!
* Previously the A2DP link would always connect @ 48000, rather than the I2S rate of 44100, and the resampled
APTX_LL audio would sound like ‘Snap, Crackle. Pop’ cereal played through a megaphone.

So thanks for improvement!

Question: If others can confirm the presence of the remaining APTX_LL intermittent pops could we have that
noise source eliminated in the next firmware release?

Thanks,
Joe

7

Joe,

I have the same click problem with BC127 acting as a I2S slave and a microcontroller acting as a I2S master. The click only occurs at playback (I2S from microcontroller to BC127).

The auto_rate did not solve the click issue.

I found out that the BC127 is very sensitive to clock precision. The click occurence is dependent on the I2S clock precision. I fed my microcontroller with a waveform generator and varied the frequency of the pulse to adjust the I2S clock frequency. I found the clock frequency range at which the clicks disappeared, it is only a 250Hz range around the nominal I2S bit clock frequency (44100 x 64).

The internal oscillator of the microcontroller is not precise enough to remove the click in the playback sound. We will install a more precise oscillator to feed the microcontroller.

My questions to Sierra Wireless :

  • What is the I2S clock tolerance of the BC127 acting as a I2S slave?
  • What exactly does the auto_rate parameter do?

Thanks

8

Hi,

The chipset documentation does not n=unfortunately specify a jitter on the pins.

Regards

Matt

9

Sorry mistake typing, they specify a jitter level, but not an accuracy. However all internal clocks are derived from the master clock which is specified for frequency accuracy and tunable with load capacitance to reduce offset which we do at production.

Regards

Matt